Population Dynamics of Staphylococcus aureus in Cystic Fibrosis Patients To Determine Transmission Events by Use of Whole-Genome Sequencing.

Strict infection control practices have been implemented for health care visits by cystic fibrosis (CF) patients in an attempt to prevent transmission of important pathogens. This study used whole-genome sequencing (WGS) to determine strain relatedness and assess population dynamics of Staphylococcus aureus isolates from a cohort of CF patients as assessed by strain relatedness. A total of 311 S. aureus isolates were collected from respiratory cultures of 115 CF patients during a 22-month study period. Whole-genome sequencing was performed, and using single nucleotide polymorphism (SNP) analysis, phylogenetic trees were assembled to determine relatedness between isolates. Methicillin-resistant Staphylococcus aureus (MRSA) phenotypes were predicted using PPFS2 and compared to the observed phenotype. The accumulation of SNPs in multiple isolates obtained over time from the same patient was examined to determine if a genomic molecular clock could be calculated. Pairs of isolates with ≤71 SNP differences were considered to be the "same" strain. All of the "same" strain isolates were either from the same patient or siblings pairs. There were 47 examples of patients being superinfected with an unrelated strain. The predicted MRSA phenotype was accurate in all but three isolates. Mutation rates were unable to be determined because the branching order in the phylogenetic tree was inconsistent with the order of isolation. The observation that transmissions were identified between sibling patients shows that WGS is an effective tool for determining transmission between patients. The observation that transmission only occurred between siblings suggests that Staphylococcus aureus acquisition in our CF population occurred outside the hospital environment and indicates that current infection prevention efforts appear effective.

An outbreak after all: Cutibacterium acnes among pediatric patients with cerebrospinal fluid diversion device infections highlights gaps in guidelines.

Objective: Cutibacterium acnes is normal skin flora but can cause sterile implant infections. We investigated a cluster of seven patients with C. acnes in anaerobic cerebrospinal fluid (CSF) cultures in November 2020. Further analysis identified a missed outbreak, highlighting ambiguity in diagnosis of indolent organisms in the 2017 IDSA meningitis guidelines. Design: Outbreak investigation. Setting: Quaternary pediatric facility. Patients: A case was defined as a hospitalized patient with C. acnes isolated from CSF culture from January 1, 2016 to December 31, 2022. Methods: We defined comparison periods based on timing of C. acnes culture positivity as 1) pre-outbreak (2016-2020), 2) outbreak (2020-2021), and 3) post-outbreak (2022). Rates of C. acnes positive cultures per 1000 CSF cultures and rate ratios were calculated by comparison periods. Results: We identified 9 positive C. acnes CSF cultures among 7 cases November 10-27, 2020, all with at least 1 CSF diversion device. The anaerobic culture media was substituted at the time of case cluster. In 2021, the culture media was implemented permanently with no increase in C. acnes culture positivity. The rate of C. acnes positive CSF cultures and rate ratio increased in the outbreak period (p=0.01) compared to pre-outbreak and post-outbreak periods. There was no difference between the pre- and post-outbreak periods. Conclusions: Retrospective analysis of CSF culture data led to reclassifying a C. acnes pseudo-outbreak as a true outbreak in CSF diversion devices at our institution. Clearer guidance is needed to delineate the role of C. acnes in CSF diversion device infections.

Adherence to Personal Protective Equipment practices during the COVID-19 pandemic: A pilot study.

A direct observational pilot project of healthcare personnel (HCP) was conducted to validate a tool that measures personal protective equipment (PPE) adherence at a large pediatric institution. Overall unit PPE adherence for all moments ranged from 50-61%. Masking was the most adhered to PPE moment (100%); hand hygiene prior to donning PPE had the lowest adherence (13%). Using data from this standardized tool, researchers can evolve PPE standards to maximize their adherence, effectiveness, and ease of utilization.

An outbreak of Burkholderia contaminans at a quaternary children's hospital linked to equipment reprocessing.

Burkholderia cepacia complex (BCC) has been increasingly implicated in local and multistate outbreaks in both adult and pediatric healthcare settings. However, a lack of source identification may be common for BCC outbreak investigations. We describe, in detail, the investigation of an outbreak of BCC (B. contaminans) among pediatric patients at a large quaternary-care children's hospital and our system-level changes and outcomes.

Reduced male fertility of an Antarctic mite following extreme heat stress could prompt localized population declines.

Climate change is leading to substantial global thermal changes, which are particularly pronounced in polar regions. Therefore, it is important to examine the impact of heat stress on the reproduction of polar terrestrial arthropods, specifically, how brief extreme events may alter survival. We observed that sublethal heat stress reduces male fecundity in an Antarctic mite, yielding females that produced fewer viable eggs. Females and males collected from microhabitats with high temperatures showed a similar reduction in fertility. This impact is temporary, as indicated by recovery of male fecundity following return to cooler, stable conditions. The diminished fecundity is likely due to a drastic reduction in the expression of male-associated factors that occur in tandem with a substantial increase in the expression of heat shock proteins. Cross-mating between mites from different sites confirmed that heat-exposed populations have impaired male fertility. However, the negative impacts are transient as the effect on fertility declines with recovery time under less stressful conditions. Modeling indicated that heat stress is likely to reduce population growth and that short bouts of non-lethal heat stress could have substantial reproductive effects on local populations of Antarctic arthropods.

Analysis of chlorhexidine gluconate in skin using tape stripping and ultrahigh-performance liquid chromatography-tandem mass spectrometry.

BACKGROUND: Topical chlorhexidine gluconate (CHG) is used widely to reduce healthcare-associated infection. The optimal therapeutic dose for maximum efficacy and reduced toxicity is unclear, in part because of the lack of analytical methods to monitor CHG levels in skin. A novel method was developed to accurately measure CHG levels in skin after topical application with the goal of determining its pharmacokinetics in skin. METHODS: Ultrahigh-performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) was used to develop a validated assay for measuring CHG levels in skin cells collected by a non-invasive adhesive tape-stripping method. CHG levels in the skin stratum corneum of healthy adult volunteers were measured at 0.5, 4, 8, and 24 h after its application. RESULTS: Conditions for extraction of CHG were optimized and the assay was linear in the range 0.1-50 µg/mL (corresponding to 0.2-100 µg chlorhexidine/tape), with an intra-assay precision of 1.74-10.50 % and a relative error of ≤10 %. The inter-assay accuracy was in the range of 5.86-10.96 % with a relative error <9 %. CHG was stable on tapes stored at 4 °C and ambient temperature for 14 and 3 days, respectively. The recovery of CHG from the tape was quantitative and the matrix effect was determined as 2.1-14.8 %. CHG levels in healthy adult volunteer skin following topical application decreased rapidly over a 24 h period. CONCLUSIONS: A rapid, accurate and specific UHPLC-MS/MS method was developed for the measurement of CHG in the skin obtained by tape stripping that was linear over a large dynamic range. This assay afforded a simple and convenient non-invasive approach to monitor CHG levels in skin after topical application that can be applied to enable the optimal dose to prevent infection and minimize toxicity.

Maximizing efficiency in a high occupancy setting to utilize ultraviolet disinfection for isolation rooms.

BACKGROUND: Ultraviolet (UV) disinfection decreases nosocomial disease rates in acute care settings; effective program implementation is poorly understood. We developed a program to UV-disinfect rooms following discharge of patients in transmission-based precautions (TBP) and assessed its effect on hospital-acquired infection (HAI) rates. METHODS: An isolation room housed a patient in any type of TBP. A priority room was an isolation room in TBP for multidrug resistant organisms or Clostridioides difficile infection. Percent rooms disinfected and HAI rates were calculated monthly. The two-robot program was started by Infection Prevention utilizing a single environmental services employee. Efficiency was increased by granting environmental services' personnel oversight, increasing coverage, and modifying shift-based goals. Our primary goal was disinfection of all discharged priority rooms. Our secondary goal was disinfection of all discharged isolation rooms. RESULTS: The program achieved 6-month disinfection averages of 85.7% of isolation, and 87.7% priority rooms, respectively. Using a dedicated UV disinfection team and setting isolation room per shift goals improved coverage. HAI rates decreased by 16.2% following program implementation. CONCLUSIONS: We implemented an effective UV disinfection program, and observed HAI reduction, by focusing on broad coverage and efficient deployment of assets without affecting patient flow or expanding the robot fleet.

Reduced isolation room turnover time using Lean methodology.

OBJECTIVE: To prevent environmental transmission of pathogens, hospital rooms housing patients on transmission-based precautions are cleaned extensively and disinfected with ultraviolet (UV) light. To do so consistently requires time and coordination, and these procedures must avoid patient flow delays and associated safety risks. We sought to improve room turnover efficiency to allow for UV disinfection. DESIGN: A 60-day quality improvement and implementation project. SETTING: A quaternary academic pediatric referral facility. INTERVENTIONS: A multidisciplinary healthcare team participated in a 60-day before-and-after trial that followed the Toyota Production System Lean methodology. We used value-stream mapping and manual time studies to identify areas for improvement. Areas addressed included room breakdown, room cleaning, and wait time between cleaning and disinfection. Room turnover was measured as the time in minutes from a discharged patient exiting an isolation room to UV disinfection completion. Impact was measured using postintervention manual time studies. RESULTS: Median room turnover decreased from 130 minutes (range, 93-294 minutes) to 65 minutes (range, 48-95 minutes; P < .0001). Other outcomes included decreased median time between room breakdown to cleaning start time (from 10 to 3 minutes; P = .004), room cleaning complete to UV disinfection start (from 36 to 8 minutes; P < .0001), and the duration of room cleaning and curtain changing (from 57 to 37 minutes; P < .0001). CONCLUSION: We decreased room turnover time by half in 60 days by decreasing times between and during routine tasks. Utilizing Lean methodology and manual time study can help teams understand and improve hospital processes and systems.

Accelerating Initiation of Adequate Antimicrobial Therapy Using Real-Time Decision Support and Microarray Testing.

INTRODUCTION: Bloodstream infections (BSI) represent a common cause of sepsis and mortality in children. Early and adequate empirical antimicrobial therapy is a critical component of successful treatment of BSI. Rapid PCR-based diagnostic technologies, such as nucleic acid microarrays, can decrease the time needed to identify pathogens and antimicrobial resistance and have the potential to ensure patients are started on adequate antibiotics as early as possible. However, without appropriate processes to support timely and targeted interpretation of these results, these advantages may not be realized in practice. METHODS: Our Antimicrobial Stewardship Program (ASP) implemented a quality improvement initiative using the Institute for Healthcare Improvement's Model for Improvement to decrease the time between a nucleic acid microarray result for Gram-positive bacteremia and the time a patient was placed on adequate antimicrobial therapy. The primary effective intervention was a near real-time notification system to the managing physicians of inadequate antimicrobial therapy via a call from the ASP team. RESULTS: Following the intervention, the average time to adequate antimicrobial therapy in patients with Gram-positive BSI and inadequate coverage decreased from 38 hours with the nucleic acid microarray result alone to 4.7 hours when results were combined with an ASP clinical decision support intervention, an 87% reduction. CONCLUSIONS: The positive effects of rapid-detection technologies to improve patient care are enhanced when combined with clinical decision support tools that can target inadequate antimicrobial treatments in near real time.

Reliability of the Verigene system for the identification for Gram-positive Bacteria and detection of antimicrobial resistance markers from children with bacteremia.

BACKGROUND: Targeted antimicrobial therapy can reduce morbidity in patients with sepsis. Molecular methodologies used in the clinical laboratory can provide information about infectious agents faster than traditional culture methods. Using molecular information to make clinical decisions more quickly has been shown to improve patient outcomes, and reduce length of stay and healthcare cost in adults. Its effect on pediatric care is less well described. METHODS: Blood cultures growing Gram-positive cocci or Gram-positive bacilli on Gram stain were evaluated by molecular and traditional methodologies. Results from the molecular platform, Luminex Verigene® Blood Culture - Gram-positive Panel (BC-GP) were compared to results from standard culture and susceptibility testing (Vitek™ MS, Vitek™, E-test®). Overall statistical agreement is evaluated. RESULTS: 1231 positive pediatric blood cultures grew single isolates detectable by the BC-GP panel. 899 were correctly identified to species, 282 to genus, 50 isolates were not detected. All organisms detected by BC-GP that grew in single isolate cultures were identified as the same organism by Vitek™ MS with the exception of 7 organisms.112 cultures were found to have polymicrobial growth of Gram-positive organisms. Excellent overall agreement was noted for antimicrobial resistance markers with only 5 samples displaying discordant results. DISCUSSION: In general, clinicians can use the identification and antimicrobial resistance marker data gained from Luminex Verigene® BC-GP with confidence to alter empiric coverage. Rare instances of disagreement with traditional culture data led to maintaining the empiric clinical approach and did not result in patient harm.

Association of visitation policy and health care-acquired respiratory viral infections in hospitalized children.

Visitor restriction policies are meant to prevent health care-acquired viral infections; however, data on their efficacy in hospitalized children are limited. We report a 37% reduction in health care-acquired respiratory viral infections in a children's hospital following standardization of the visitation policy that limited the number of visitors during a patient's hospitalization.

Risk Factors for Staphylococcus aureus Acquisition in the Neonatal Intensive Care Unit: A Matched Case-Case-Control Study.

OBJECTIVE To determine risk factors independent of length of stay (LOS) for Staphylococcus aureus acquisition in infants admitted to the neonatal intensive care unit (NICU). DESIGN Retrospective matched case-case-control study. SETTING Quaternary-care referral NICU at a large academic children's hospital. METHODS Infants admitted between January 2014 and March 2016 at a level IV NICU who acquired methicillin resistant (MRSA) or susceptible (MSSA) S. aureus were matched with controls by duration of exposure to determine risk factors for acquisition. A secondary post hoc analysis was performed on the entire cohort of at-risk infants for risk factors identified in the primary analysis to further quantify risk. RESULTS In total, 1,751 infants were admitted during the study period with 199 infants identified as having S. aureus prevalent on admission. There were 246 incident S. aureus acquisitions in the remaining at-risk infant cohort. On matched analysis, infants housed in a single-bed unit were associated with a significantly decreased risk of both MRSA (P=.03) and MSSA (P=.01) acquisition compared with infants housed in multibed pods. Across the entire cohort, pooled S. aureus acquisition was significantly lower in infants housed in single-bed units (hazard ratio,=0.46; confidence interval, 0.34-0.62). CONCLUSIONS NICU bed design is significantly associated with S. aureus acquisition in hospitalized infants independent of LOS. Infect Control Hosp Epidemiol 2018;39:46-52.